1. Field of the Invention
The invention relates to an interlocking device, more particularly to an interlocking device adapted to be mounted on an electronic apparatus.
2. Description of the Related Art
As shown in FIG. 1, an electronic apparatus, such as a notebook computer, an electronic translation machine and a personal digital assistant, includes a case 9 that has a lower case portion 91 and an upper case portion 92 pivoted to the lower case portion 91, and an interlocking device 93 for interlocking the lower and upper case portions 91, 92. The upper case portion 92 is rotatable about an axis (X) relative to the lower case portion 91 between a position of use and a closed position. The interlocking device 93 includes a first interlocking member 94 mounted slidably on a front end 921 of the upper case portion 92, and a second interlocking member 95 mounted on a front end of the lower case portion 91. The first interlocking member 94 includes a spring-biased button 942 protruding outwardly from the front end 921 of the upper case portion 92, and a hook 941 extending downwardly from the button 942. The second interlocking member 95 is formed with a retaining groove formed in the front end of the lower case portion 91. 
The first interlocking member 94 is slidable in a direction (Y) parallel to the axis (X) between a locked position and an unlocked position. When in the locked position, the hook 941 engages the retaining groove, thereby preventing rotation of the upper case portion 92 from the closed position to the position of use. When in the unlocked position, the hook 941 disengages from the retaining groove, thereby permitting rotation of the upper case portion 92 from the closed position to the position of use.
Since the button 942 is slid against an urging member (not shown) in the aforesaid direction (Y) to the unlocked position, the force exerted to offset the urging force of the urging member still has to be maintained before another direction of force is exerted to rotate the upper case portion 92 about the axis (X) to the position of use. That means, to complete the opening operation, the user needs to conduct the unlocking and opening operations with both hands. Moreover, with the rapid advancement in technology, the case 9 of the electronic apparatus is getting smaller and lighter. As such, when the user opens the upper case portion 92 with both hands without stabilizing the lower case portion 91 simultaneously, there is a chance that the lower case portion 91 will be undesirably moved upwardly together with the upper case portion 92.